Abstract: A method of randomizing a size of a packet is provided. A randomization method may include recognizing a maximum segment size (MSS) defined for transmission and reception of a packet with a reception terminal, and randomizing a size of the packet to be less than the MSS.

Abstract: A signal processing technology for allowing a repeater to transmit a signal received from an external apparatus to a terminal is provided. In a satellite system, a signal transmitted from a satellite or transmitted to a satellite is subject to a low order modulation, and a terrestrial repeater performs a high order modulation on signals and retransmits the signals.

Abstract: A wireless power charging apparatus and method are provided, which recognizes location information of at least one wireless power receiving apparatus; selects at least one of at least one wireless power transmitter that supplies power to the at least one wireless power receiving apparatus based on the location information; and supplies power to the at least one wireless power receiving apparatus through the at least one selected wireless power transmitter.

Abstract: A weather satellite information processing algorithm simulation system and method are provided. The weather satellite information processing algorithm simulation system may include a data supplying unit to supply input data that is required to operate a weather satellite information processing algorithm, an algorithm operator to operate the weather satellite information processing algorithm, using the supplied input data, and a result analyzer to analyze a result obtained by operating the weather satellite information processing algorithm, and to generate analysis result data. The weather satellite information processing to algorithm may extract a product from weather satellite information stored by a weather satellite earth station.

Abstract: In a system where satellite communication using multi-beams is performed for each group including a plurality of beams, a required data transmission rate of each beam is detected for each group, more traffic resources are allocated to a beam having a higher required data transmission rate than other beams based on the detection result, and data traffic transmitted to each beam in the group is adaptively controlled.

Abstract: Disclosed are an apparatus and a method for normally receiving data by accurately estimating and compensating for a frequency offset for a wireless frequency channel through which data are transmitted in a communication system under wireless frequency environment. In the present invention, data transmitted through the wireless frequency channel are received, the frequency offset in the wireless frequency channel from the receive data is estimated based on an interpolation scheme using the periodogram, and the frequency offset is compensated to receive the data by frequency-synchronizing with the wireless frequency channel.

Abstract: Disclosed is a communication method of a satellite mobile communication system. The communication method of a satellite mobile communication system, includes: receiving system information indicating frame intervals in which first user equipments using a satellite radio interface in commonality with a terrestrial radio interface do not perform communications from a base station; accessing the base station in the rest frame intervals other than frame intervals in which the first user equipments do not perform communications, based on the system information; transmitting the system information from the base station to second user equipments using a satellite radio interface optimized for satellite environment; and accessing the base station in the rest frame intervals based on the system information received in the second user equipments.

Abstract: A diversity method using an error correcting code. The diversity method includes creating a mother code by performing error correction coding on an input bit string to be coded, puncturing the created mother code and acquiring an error correcting code including systematic information and partial parity information, and space-time encoding the acquired error correcting code corresponding to each frequency.

Abstract: In a system that performs mobile communication using at least two beams, by determining a size of a beam based on information that is acquired for mobile terminals attempting an access, a beam of a form having an adaptive size is formed and thus communication is performed. A beam sector including a plurality of beam segments and a beam segment that forms a beam of a minimum size within entire coverage is set, and while forming one beam per beam sector, a size of a beam is adaptively determined.

Abstract: Provided is a satellite communication system for obtaining a diversity gain by transmitting a signal applied with STBC. When a signal transmission band of a link between a satellite and a terminal differs from that of a link between a satellite and a repeater, the satellite communication system includes: a satellite for transmitting a first signal encoded to STBC using a band of a link formed between the satellite to a terminal and transmitting a second signal encoded to STBC using a band of a link formed between the satellite to a repeater; and at least one of frequency transforming repeaters for receiving the second signal through the band of the link formed between the satellite to the repeater, transforming the received second signal to a signal with other frequency band, and transmitting the transformed second signal using a band of a link formed to a terminal.

Abstract: According to the present invention, a random access method between a terminal and a base station comprises: a system information transmission step in which the base station transmits, to the terminal, system information including route values sequentially selected from among a set of routes; a random access preamble transmission step in which the terminal generates a random access preamble on the basis of the system information and transmits the generated random access preamble to the base station; a period setup step in which the base station sets a period available for an arrival of the random access preamble; and a random access preamble detection step in which the base station detects the random access preamble in said available period.

Abstract: Provided is a method of establishing an uplink in a mobile satellite communication system, the method including: receiving a random uplink access signal from terminals included in a coverage of a satellite beam; estimating a location of each of the terminals; calculating an uplink transmission point in time when each of the terminals transmits an uplink signal, based on the estimated location of each of the terminals; transmitting, to each of the terminals, the calculated uplink transmission point in time; and receiving the uplink signal from each of the terminals at the calculated uplink transmission point in time.

Abstract: Provided are an apparatus and method for providing position information, and a user terminal and method for outputting position information. The apparatus for providing position information includes a first position information calculator configured to calculate first position information of mobile object using at least three signals received from at least three signal transmission devices, a second position information calculator configured to calculate second position information of the mobile object by mapping the calculated first position information of the mobile object to information on the mobile object's surroundings, and a position information transmitter configured to transmit the calculated second position information of the mobile object to a terminal.

Abstract: A power controlled adaptive modulation and coding (AMC) scheme in a satellite communications system includes: calculating, by a user terminal, a received signal-to-noise ratio (SNR) through a packet received from a base station; removing a power control level applied to a packet received before the received packet from the calculated received SNR, and deciding the value obtained by decreasing the calculated received SNR by the power control level; deciding an AMC mode based on the decided received SNR; determining whether power control is required, and deciding a required power control magnitude depending on a channel state positioned in the AMC mode range; transmitting the decided AMC mode and the decided power control information to the base station through channel quality indicator (CQI) feedback; and applying the AMC mode based on information received, and increasing a power by a power control magnitude decided from the received information.

Abstract: In the present invention, a GPS reference station generates and transmits GPS error correction information for each wireless AP and a user terminal recognizes the GPS error correction information to be used for correcting reception information of a user terminal GPS receiver, thereby acquiring precision positioning performance.

Abstract: First resource blocks of a radio resource each include a first number of subcarriers and a second number of subframes having the first size. In this case, second resource blocks are formed, each second resource block including fewer subcarriers than the first number and fewer subframes than the second number based on the first resource blocks. A signal is transmitted in the first resource block or second resource block, and particularly, signals of first and second channels are transmitted by sharing the first resource block.

Abstract: The present invention relates to a communication method in a mobile communication system. An exemplary embodiment of the present invention provides a mobile satellite communication system having a complementary terrestrial component among various mobile communication systems. The mobile satellite communication system can simultaneously provide a communication service and a broadcasting service to a terminal according to integration between communication and broadcasting. Different signal transmission methods are used between the complementary terrestrial component and a satellite. Specifically, a time division duplex method and a frequency division duplex method are used together and resources are allocated. As a result, system throughput can be increased, and local broadcasting contents can be effectively transmitted to the terminal.

Abstract: The present invention relates to a system and method of reusing radio resources capable of improving radio resource efficiency. According to an embodiment of the present invention, in a communication system including a repeater that retransmits signals transmitted from a satellite to user terminals, it is possible to reuse some of the radio resources used in a wide area coverage, such as the satellite, in a repeater coverage. Therefore, it is possible to ensure radio resources such that repeater data can be transmitted to user terminals without additional radio resources.

Abstract: Disclosed is a hierarchical random access method for a wireless communication system having a significantly large cell. According to the present invention, a length of a preamble sequence and a length of a reference slot may be designed based on a terminal having greatest capacity of adjusting a timing error arrived at a base station, and a slot length may be designed to be an integer multiple of the length of the reference slot depending on a timing error correction capacity, thereby enabling terminals to use various slot lengths.

Abstract: An apparatus and method for generating brain waves for dieting of a user are disclosed. The brain wave generating apparatus may include a brain wave detection unit to detect whether brain waves related to an increase in appetite are generated from a user; and a brain wave generation unit to generate brain waves related to suppression of appetite when the brain waves related to the increase in appetite are generated from the user.